1. Field of the Invention
The present disclosure is related to air cavity packages. More particularly, the present disclosure is related to air cavity packages having high thermal conductivity base plates and methods for making such base plates.
2. Description of Related Art
Semiconductor dice and transistors are often packaged or enclosed to protect the die or transistor from one or more environmental conditions.
One such package includes an air cavity package, which typically includes one or more semiconductor dice or transistors mounted directly on a base plate and an insulated frame surrounding the die or transistor. A lid is placed over the frame, sealing the die or transistor in a cavity of air. In addition to the structural aspect of the base plate for mounting the dice and transistors, the base plate is used to assist in removing heat from the die or transistor by conduction.
Air cavity packages are widely used to house high frequency devices such as radio-frequency or RF dice and transistors. The power densities of such dice and transistors continue to increase. Thus, it has been determined by the present disclosure that there is a need for increases in the heat dissipating capacity of packages, particularly of base plates.
In use, air cavity packages undergo numerous high temperature heat cycles. Thus, in addition to having a high heat dissipating capacity, the base plates must also have a coefficient of thermal expansion (CTE) that matches those of the die or transistor and the frame. Minimizing CTE mismatch among the package components is desired to mitigate failure and fatigue of the components that can result from temperature cycling.
Accordingly, there is a continuing need for air cavity packages and base plates that overcome, alleviate, and/or mitigate one or more of the aforementioned and other deleterious effects of prior art packages.